net: Add fuzzer for HostResolverImpl.

net/dns/dns_session_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/dns/dns_session.h"
 
 #include <list>
 #include <memory>
 #include <utility>
 
@@ skipping 71 matching lines @@
   NetLog::Source source_;
 
  private:
   bool ExpectEvent(const PoolEvent& event);
   std::list<PoolEvent> events_;
 };
 
 class MockDnsSocketPool : public DnsSocketPool {
  public:
   MockDnsSocketPool(ClientSocketFactory* factory, DnsSessionTest* test)
-     : DnsSocketPool(factory), test_(test) { }
+      : DnsSocketPool(factory, base::Bind(&base::RandInt)), test_(test) {}
 
   ~MockDnsSocketPool() override {}
 
   void Initialize(const std::vector<IPEndPoint>* nameservers,
                   NetLog* net_log) override {
     InitializeInternal(nameservers, net_log);
   }
 
   std::unique_ptr<DatagramClientSocket> AllocateSocket(
       unsigned server_index) override {
@@ skipping 138 matching lines @@
 TEST_F(DnsSessionTest, HistogramTimeoutLong) {
   config_.timeout = base::TimeDelta::FromSeconds(15);
   Initialize(2);
   base::TimeDelta timeout = session_->NextTimeout(0, 0);
   EXPECT_EQ(timeout.InMilliseconds(), config_.timeout.InMilliseconds());
 }
 
 }  // namespace
 
 } // namespace net